Process for glazing and hardening brick, terra-cotta, and other objects.



*InoN nAs'It. nsNNIsoN, or so 'rrr sAN FRANCISCO, CALIFORNIA.

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No Drawing.

To all whom, it'mag concern:

Be itrknown that I," LEONIDAS It. DEN- NISON, a citizen of the United States, and a resident of the city of South San Francisco, county of San Mateo, State of California, have made a new and useful inventionto Wit, a Process for Glazing and Hardening Brick, Terra-Gotta, and other Objects; and I do hereby declare the following to be a full, clear, concise, and exact description thereof.

My invention relates to a special form of treatment of the surface of such products as brick, terra cotta, and other fictile articles, stone, concrete and other materials for glazing and hardening such surfaces, and also coloring them.

My invention also relates to the products produced by such treatment. v

Several processes for glazing the surface of fictile articles are now in use. One of these processes-consists in applying a glazing solution to the surface of the articles and then baking the articles in a furnace until the solution fuses and forms a glaze on the surface of the articles.

Another process consists in placing the articles in a furnace and then throwing salt into the fire in the furnace which volatilizes and forms a glaze on the surface of the articles.

In these processes the heat which is applied to the surface of the articles is not great enough to fuse the surface material of the articles under treatment. The glaze solution and salt forms a layer on the surface of the articles with a consistence different from that of the articles and does not integrate with the materials of the articles. This glaze layer cracks very easily upon coming in contact with other objects and peels off, while the different consistencies of the glaze and the articles gives the glaze and the articles different co-eflicients of expansion, which causes the glaze to crack and peel off during expansion and contraction of the glaze and the articles. Moreover, the present glazing processes require a considerable amount of time and are expensive as well as inefficient.

My invention may be carried out in various ways and I intend this specification and the appended claims to cover the same in whatever way it may be carried out.

In its simplest form it contemplates generally the process of applying directly to Specification of Letters Patent.

Patented Uct. 26,1915.

- Application filed January 9, 1915. Serial No. 1,421.

the surface ofthe articles treated, without the use of any glazing solution or preparation, a fiame of such heatintensity as is suflicient to fuse the materials of said arti cles at the surface and to integrate them with the body of the materials constituting the articles, so as to produce a glazed'and hardened surface impervious to moisture and acids and to make the surface and body of the articles of a substantially homogeneous consistency. The degree of heat required varies with different, articles according to their fusibility, but the basic principle is that the heat must be sufiicient to fuse the surface materials of the particular article under treatment. In treating ordinary clay building bricks and ornamental terra cotta, I have found that a flame having an intensity of approximately six thousand degrees Fahrenheit is efiicient for my purpose. The simplest method of practising the invention is to apply the flame directly to the surface of the article under treatment through the medium of a torch, such as the well known oxygen acetylene torch used in welding metals. The article under treatment may be held stationary and the flame of the torch be passed over the surface; or the article may be placed in a frame or rack and moved under the flame of the torch while the latter is held stationary. The shape of the flame may be varied by varying the form of the torch nozzle. For instance, circular, flat, crescent-shaped, or any desired form of nozzle may be used, thereby producing correspondingly shaped flames. I also contemplate applying in some instances to the surface of the articles under treatment coloring, or other preparations, prior to the fusing operation, and in such cases the fusing of such preparations will be coincident with the fusing of the surface material of the article under treatment, whereby the two become integrated. For example, a coloring preparation may be applied and thereby a desired color may be given to the article, whereby I not only pro- 'duce the glazed and hardened surface which is the main object of my process, but one having any desired color. I also contemplate in some instances applying to the article under treatment other compositions, such for example as metals and silicious minerals irrespective of color, whereby different chemical reactions occur through the influence of the flame. Or those difi'erent ingredients may be mixed with or incorporated into the material of the fictile articles while in a plastic state before molding and then the flame may be applied directly to their surface as above pointed out.

By my invention the integration of the surface material of the article under treatment into and with the body material thereof produces a glazed hardened surface which will not crack or peel off from expansion and contraction or' from jar or shock or concussion, and is also rendered impervious to moisture, and at the same time any desired color may be imparted to the surface. In practice on ordinary red clay building bricks I have by my invention produced surfaces having the useful properties above specified and also showing delicate shades of bronze, brown, purple, green and other colors, thereby doubling or trebling their value.

I also contemplate applying my process to the surface of concrete and stone buildings and other structures in place.

I claim:

1. The process of treating fictile and like articles which consists in applying an oxygen-acetylene flame to the surface thereof so as to fuse the surface material and integrate said material with the body material of the article.

2. The process of treating fictile and like articles which consists in applying a glazing preparation to the surface of such articles and applying a flame of great intensity to the exposed surface so as to fuse said preparation with the surface material and to integrate them with the body material of the article.

3. The process of treating fictile and like articles which consists in applying a coloring preparation to the surface of such articles and applying a flame of great heat intensity to the exposed surface so as to fuse said preparation with the surface material and to integrate them with the body material of the article.

4. The process of treating fictile and like articles which consists in mixing a hardening element in the plastic material of said articles before molding and applying a flame of great heat intensity to the exposed surface of said articles after molding so as to fuse the surface material and integrate said material with the body material of the article.

5. The process of treating fictile and like articles which consists in mixing a coloring material in the plastic material of said articles before molding and applying a flame of great heat intensity to the exposed surface of said articles after molding so as to fuse the surface material and integrate said material with the body materialof the article.

(3. The process which.consists in impinging an oxygen-acetylene flame directly upon the surface of fictile and like products until the surface material is fused together and integrated with the body material of the product.

7. The process which consists in impinging a flame of a temperature substantially 6000 Fahrenheit directly upon the surface of fictile and the like products until the surface material is fused together and integrated with the body material of the product.

8. The process of treating fictile and like materials which consists in applying a glazing preparation to the surface of such material and applying an oxygen-acetylene flame to said preparation and said surface until said preparation and the surface and body of the material fuse together.

9. The process of treating fictile and like material which consists in applying a coloring preparation to the surface of fictile and like material and applying an oxygen-acetylene flame to said surface until said preparation and the surface and body of the material fuse together.

10. The process of treating fictile and like articles which consists in mixing a hardening element in the plastic material of said articles before molding and applying an oxygen-acetylene flame to the surface of said articles after said articles are molded until the surface and body materials of said articles fusev together.

11. The process of treating fictile and like articles which consists in mixing a coloring element in the plastic material of said articles before molding and applying an oxygen-acetylene flame to the surface of said articles after molding until the surface and body materials of said articles fuse together.

In testimony whereof, I have hereunto set my hand at San Francisco, California, this 5th day of January 1915.

LEONIDAS R. DENNISON.

In presence of ALAN FRANKLIN,

P. S. PIDWELL. 

